CTA riders enrolled in a pre-tax transit program who haven't switched to Ventra must transition by Friday, the CTA said Wednesday.

Starting Friday, Chicago Card Plus users who pay for transit using pre-tax funds through their employee benefits will have to use their Ventra cards to access these funds. These programs allow riders to pay for their commute using pre-tax income.

"While most employees have made the switch to the modern, account-based fare payment system, the CTA wants to remind the small number of employees still using their Chicago Card Plus cards that the time to switch to Ventra is now," the CTA said in a release.

In the fall, some company administrators complained about the Ventra commuter benefits website, saying that employees were being associated with the wrong employers, the Tribune reported.

Chicago Card Plus users not enrolled in these programs can still use their Chicago Cards until June 1 though riders won't be able to reload Chicago Cards after May 1.

About 82 percent of CTA rides are paid for by Ventra, the CTA said. Riders who have disposable magnetic stripe cards can use them until July 1, when CTA plans to fully transition to Ventra.